The invention relates to a mixing device for mixing a first gas flow with a second gas flow in a turbofan engine, having an actuating device and walls that bound a radially inner-lying channel for the first gas flow and a radially outer-lying channel for the second gas flow, the actuating device comprising a coupling element that is coupled to the walls, the actuating device being designed to pivot the walls from a first position to a second position disposed radially outside relative to the first position by means of the coupling element.
In turbofan engines, a noise reduction and a reduction of specific fuel consumption can be achieved by mixing a mantle flow of a fan and a core flow of an aircraft gas turbine. Conventionally, mixing takes place via a mixing device having a meandering profile that is positioned downstream behind a low-pressure turbine of the aircraft gas turbine, this mixing device alternately deflecting at least one partial flow of the mantle flow radially inward and at least one partial flow of the core flow radially outward. Such mixing devices, called bloom mixers, based on their meandering profile, are shown, for example, in DE 10 2010 014 909 A1 or DE 10 2010 014 910 A1. In order to be able to adapt the mixing device to different operating points, the profile of the mixing device is varied. The direction of deflection of the core flow or of the mantle flow can be varied here by means of a flexible wall structure that is widened or constricted by an actuating device. The direction of deflection, however, is limited in these mixing devices by the elasticity of the material.